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Aug. 19 1924. 1,505,478

A, MACHA APPARATUS FOi? TREATING HOT WIRE ELEMENTS FOR ELECTRICAL DEVICES Filed Dec. 9, 1922- ATTORNEY Patented Aug. 19, 1924.

UNITED STATES PATENT oFFicE- AUGUST Iv'IAOHA, 0' CLEVELAND, OHIO, ASSEGNQR TO THE ELECTRIC CONTROLLER 8c MANUFACTURING COBIPAEY, Q6? CLEVELAND, ()I-TIG, A @QBPORATION OF OHIO.

To all whom it may concern:

Be it known that I, Anonsr lilacrm, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and Stat of Ohio, have invented new and useful improvements in .z'ipparatns for 'l reating Hotire Elements for Electrical Devices, of which the following is a specification.

My invention relates to apparatus for straightening and aging hot-wire elements for electrical devices. Hot-wire elements are used for many purposes, as to control the opening and closing of electric switches, to operate indicators of various kinds of electric meters, and the like. In such devices a length of wire having suitable electrical re sistance is usually placed under a stretching strain in the circuit to be controlled or measured; and by its expansion a certain distance due to its heating by the current flowing therein causes or permits an electric switch to open or an indicator to move in a certain direction, and by its contraction upon cooling to a definite degree to return the switch to its closed position, or to move the indicator in the opposite direction. It has been found that wire untreated by my invention is more or less crooked, and that it stretches more or less after its incorporation for use in electrical devices. It is the object of my invention to provide an apparatus and method for permanently removing the orookedness of such wires, and for stretching and heating such wire prior to its economic use so as not only to eliminate its crookedness but also to cause it to elongate to such a degree and to rea-cjust its internal structure in such a manner, as to give it a permanent set, whereby in economic use its length will not materially change except in accordance with desired eftects produced by heat due to the electric current therein. By my invention wire of definite or indefinite length may be prepared whch have definite characteristics resulting in reliable operations with little or no necessity for adjustments due to further straightening and aging of the wire.

The accompanying drawing shows a diagram oil my invention applied to the treatment of definite length of wire.

On the drawing 1 designates a transformer core having the primary winding 2 and the secondary winding 8. winding 2 is connected by the wires ELEMENTS ELECTRICAL DEVICES.

Serial IEO. 605,848.

the line switch 6 and the switch 7 to the altcijnating current supply lines 8 and 9. The switch has the movable contact 10 a ranged to engage any one of the taps 11 taken at se lected points on the winding 2.

12 is the wire to be treated for use as a hot-wire element. its ends may be provided with the loops 13 and 14-, the former being connected to one terminal of the winding 3 and surrounding the rod or bar 15, and the latter to the pin 16 carried by the lever 1.7 between its pivot 18 and its tree end which is supplied with the pin 19 to receive the hook 2O sun iortin the aendent we ht 21.

The wire is thus put under a definite stretchin strain dependent upon the mass of the J weight 21, which is selected to produce such a strain on the wire 12 that it will, under the current supplied thereto, receive such characteristics as will prevent, during the use for which it may be designed, any changes of length other than those due to its heating by the current therein.

22 is an overthrow switch designed for automatic interruption of the current in the wire 12 when the wire has elongated a definite distance. It has the spring contact member connected to the remaining terminal of the winding 3 and it has the movable member 2 -i pivoted at one end on the pin and having its tree end adapted to be engaged with, and disengaged from, the contact he lever 1"? and member 2%, connected together by the wire 32. 26 is lever pivoted on the pin 27 and having at its free end the fork members or lingers 28 and 29, between which the switch menu-- ber 24 lies. The tree end of the lever 17 lies above the lever 26 such a distance that, when the wire 12 has elongated a predetermined distance. the said end of the lever 17 will force the lever 26 downwardly until the linger 28 by engagement with the switch member 2% forces the latter downwardly enough to cause the spring 30, having one end connected to an intermediate portion of the member 2% and the other end to the lever 26 between the members 28 and 29, to pass the pivot 25, at which time the spring will throw the member 24 to the its dotted position against the stop 31, thereby opening the switch 22. In case the overthrow spring 30 tails to operate the switch, the continued lowering of the member 28 will positively open the switch. The member 24 may be returned to its upper position by the lower finger 29 when the lever 26 is returned to its upper position, in which it may be retained by any suitable means as by friction on the pin 27 or by other suitable device.

The switch 22 is useful for interrupting the current automatically when the treatment of the wire should terminate, but it could be omitted, and the lever 17 or the weight 21 could operate an indicator or alarm in a well known manner, for appris ing an attendant oil the completion of the operation. After the opening of the switch 22 the wire 12 is allowed to cool under the strain of the weight 21., thus aging the wire, giving it a permanent condition for future use as a hot-wire element in electrical apparatus. The wire 12 in coelinp contracts and lifts the weight 21, but the contact 22 remains open until closed by the operator after the finished wire has been. replaced by another to be treated. The amount of current to be transformed may be regulated by the switch 7.

I claim 1. In apparatus for straightening or aging hot-wire elements for electrical purposes, means for subjecting the wire to a predetermined stretching strain, means for causing electric current to flow in the wire for heating the same, and means for interrupting the wire-heating current when the wire has elongated a definite distance.

2. In an apparatus for straightening or aging hotwire elements for electrical purposes, means for subjecting the wire to a predetermined stretching strain, means for causing electric current of predetermined value to flow in the wire for heating the same, and means for interrupting the wireheating current after the wire has elongated a definite distance.

3. In an apparatus for straightening or aging hot-wire elements for electrical purposes, means for subjecting the wire to a predetermined stretching strain. means for causing electric current to flow in the wire for heating the same, and means for interrupting the wire-heating current when the wire has received a predetermined set.

In testimony whereof I hereunto a-flix my signature this 5th day of December, 1922. AUGUST MAUI-IA. 

